This invention relates to vacuum breakers.
Vacuum breakers have been used in various water and plumbing systems to prevent a back flow or back siphoning of water from the outlet end of a hose or other water outlet. This can occur when a lowered pressure from the water source is encountered and an elevated pressure is encountered at the discharge or outlet of the water system.
Under such a condition, reverse flow can occur from the discharge end of the water system into the water supply. This can under certain conditions, result in contamination being introduced to the water supply system.
In order to prevent this back flow situation, hydrants or other fluid couplings are sometimes provided with vacuum breakers and back flow preventers. These devices sense a reverse pressure in the system and relieve the pressure so that fluid does not flow backwards into the water supply system through the hydrant.
Therefore, a primary object of the present invention is the provision of an improved vacuum breaker.
A further object of the present invention is the provision of an improved vacuum breaker which utilizes a single elastomeric sealing member for accomplishing both the vacuum breaking function and the back flow preventing function.
A further object of the present invention is the provision of a device which is reliable throughout extensive operation.
A further object of the present invention is the provision of a device which is sensitive to small differentials in pressure, and responds to small differentials in pressure so as to move from its normal to its back flow preventing positions.
A further object of the present invention is the provision of a device which is economical to manufacture, durable in use and efficient in operation.